Counter. Sorry, didn't want all this hard work to be put to waste.

Sale 1. (22-10-2016)

Looks like he sold for some unknown amount of pure to unbox.

http://backpack.tf/profiles/76561197987317160#!/compare/1477094400/1477180800

no outpost.

Sale 2. (22-11-2016)

Sold for a Cloud 9 Modest Pile of Hat.

http://backpack.tf/profiles/76561198203537236#!/compare/1479772800/1479859200

no outpost.

Using to price modest.

Sale 3. (31-10-2016)

Sold for a duped Phosphorous Bubble Pipe(45).

X = 45 Keys

http://backpack.tf/profiles/76561198077224046#!/compare/1477872000/1477958400

no useful outpost.

Mini for Bubble Pipe.

Sold for an Anti-Freeze Ye Oiled Baker Boy(45).

http://backpack.tf/profiles/76561198077224046#!/compare/1477699200/1477872000

Mini for Baker Boy

http://backpack.tf/suggestion/5845d76886674713612d1a54

Sale 4. (01-11-2016)

Sold for a Miami Nights Das Ubersternmann(37).

X = 37 Keys

http://backpack.tf/profiles/76561198143388279#!/compare/1477872000/1477958400

no outpost.

Mini for the Ubersternmann.

http://backpack.tf/suggestion/5841def486674729b55701ec

Sale 5. (02-11-2016)

Quicksold for 34 Keys + 0.75 of sweets.

http://backpack.tf/profiles/76561198143388279#!/compare/1477958400/1478044800

http://www.tf2outpost.com/trade/28578588

Sale 6. (11-11-2016)

Bulk quicksell.

http://backpack.tf/profiles/76561198243530442#!/compare/1478736000/1478822400

http://www.tf2outpost.com/trade/28581108 - not helpful

Sale 7. (24-10-2016)

Quicksold for X amount of keys.

http://backpack.tf/profiles/76561198035278233#!/compare/1476921600/1477958400

http://www.tf2outpost.com/trade/28533664

Sale 8 (20-11-2016)

Quicksold for 26 Keys?

http://backpack.tf/profiles/76561198203537236#!/compare/1479600000/1479686400

http://www.tf2outpost.com/trade/28562107

Sale 9. (24-11-2016)

Sold with a Specialized Killstreak Sharp Dresser for a Power Surge Détective Noir + Genuine Professional Killstreak Sharp Dresser.

X + 1.3 = 31 + 5.25

X = 35 Keys

http://backpack.tf/profiles/76561198150406851#!/compare/1479945600/1480032000

http://www.tf2outpost.com/trade/28626614

The sale happened right before the Noir got dropped by 20 keys. Oh well.

Sale 10. (25-11-2016)

Quicksold

http://backpack.tf/profiles/76561198045528305#!/compare/1479945600/1480032000

Sale 11. (26-11-2016)

Quicksold for 35 Keys.

http://backpack.tf/profiles/76561198045528305#!/compare/1480032000/1480118400

Sale 12. (03-12-2016)

Sold for a Chiroptera Venenata Liquidator's Lid worth 55 Keys

https://backpack.tf/profiles/76561198328842462#!/compare/1480723200/1480809600

http://www.tf2outpost.com/trade/28632185 - B/O 55k

Sale 13. (04-12-2016)

Sold for a Strange Nuts n' Bolts Cotton Head + 9 keys.

X = 30 + 9

X = 39 Keys

http://backpack.tf/profiles/76561198117646079#!/compare/1480809600/1480896000

http://www.tf2outpost.com/trade/28642878

Mini for Cotton Head.

Sold for a Memory Leak Engineer’s Cap + 10 Keys.

X = 20 + 10

X = 30

http://backpack.tf/profiles/76561198165205268#!/compare/1480723200/1480809600

Mini for Engy Cap.

Sold for a Neutron Star Cranial Carcharodon + 3 keys + 2 ref sweets.

X = 16.5 + 3 + 0.07

X = 19.57 (rounding up to 20)

http://backpack.tf/profiles/76561198078306332#!/compare/1478649600/1478822400

Sales at 26, 34.75, 35, 36, 37, 39, 45 and 55. Sale at 39 quicksold in a day, 37 sold for an item that dropped by 20 keys right after, and other sales were quicksales. Therefore taking as 45-55.